Field of the Invention
This invention relates to firearms.
More particularly, the present invention relates to bolt action type rifles.
In a further and more specific aspect, the instant invention concerns means and method for increasing the rigidity of a rifle action receiver and, therefore, the accuracy of the rifle.
Prior Art
Over the past several decades, the bolt action rifle has achieved eminence as a military weapon and as a sporting arm. Commercially produced by numerous domestic and foreign manufacturers, bolt action rifles are available in various calibers and design configurations. All bolt action rifles, individual variations not withstanding, are analogous.
The typical bolt action rifle, in general similarity to other rifles of diverse character, comprises an action, a barrel and a stock. Peculiarly, the action includes an elongate, tube-like housing referred to as the receiver. A forward receiver ring and a rear receiver ring reside at respective ends of the receiver. A tang, which receives the rear action screw, extends rearwardly from the rear receiver ring. An elongate opening is formed into the upper side of the receiver intermediate the rings. In a repeating type rifle, the opening functions as an ejection port and for manual single loading. A receiver port is formed on the underside of the receiver through which a cartridge can be fed from a magazine.
The rear end of the barrel is affixed, usually threadedly engaged, within the forward receiver ring. A bolt, usually having a radially projecting actuating handle, is reciprocally carried within the receiver for engaging a cartridge and urging the cartridge into a chamber at the rear end of the barrel. The action and barrel assembly are supported upon a stock, typically unitary members extending between a forward portion and a rearward portion, termed the forearm and the butt, respectively. The action is located intermediate the forearm and the butt, with the receiver port in alignment with a magazine opening formed in the stock.
Owing to certain inherent characteristics, the bolt action rifle is favored as a sporting arm. For example, the action operates smoothly and reliably while permitting the construction of a rifle having pleasing lines. The action is also relatively strong. As a result of the interlocking of the bolt with the receiver, the action is able to withstand the pressures generated by modern high power cartridges.
Under field conditions, the weight of a rifle is an exceedingly important factor. Not only must the rifle be carried for extended periods of time, it must be moved quickly, frequently by an arm weary hunter, to track a rapidly fleeing game animal. Capable of being produced in calibers appropriate for large game and yet having a weight frequently of around seven pounds, or even less, the bolt action rifle is ideally suited as a hunting weapon.
The typical bolt action utilized in a conventional field or hunting rifle in meeting the requirement for light weight, however, lacks rigidity. Theoretically the receiver is an elongate generally tubular member. After removal of sufficient material to create the receiver port and the ejection port, the intermediate portion of the receiver is reduced to a pair of side rails of tenuous cross-section. At the crucial time of the firing of the rifle, the rails flex in response to the induced stress thereby enhancing inherent barrel vibrations with attendant loss of accuracy.
The article, "The Rigidity of Benchrest Actions", authored by Stuart Otteson and appearing in the May-June 1981 issue of Rifle Magazine for Shooters, discusses the rigidity of various commercial and custom rifle actions and sets forth a method of calculating rigidity. Reference is also made to "The `Rigid Look` as Built Into Bench-Rest Actions", Stuart Otteson and John Eaton, The American Rifleman, December 1976.
Subject to design criteria imposed by individual manufacturers, commercially available bolt actions exhibit wide variance in rigidity. The Winchester Model 70 receiver is fabricated from stock of generally rectangular cross-section, resulting in relatively deep siderails. Being one of the most rigid standard designs, the Model 70 is calculated to have a rigidity number of 1.5.times.10.sup.6. The Remington Model 700 receiver, on the other hand, having a substantially cylindrical cross-section displays a rigidity of 0.5.times.10.sup.6. It is noted that the Winchester receiver weighs approximately 19.3 ounces while the Remington counterpart weighs approximately 15 ounces.
Rigidity values as set forth above are inadequate for certain uses such as varmint hunting and target shooters. Accordingly, various methods have been developed to stiffen and stabilize the receiver. According to one such method, the receiver is encased in an aluminum sleeve. Adding approximately 16 ounces to the weight of the receiver, and blocking off the receiver port thereby imposing single shot limitation, the conversion raises the rigidity of the Remington Model 700 to 3.3.times.10.sup.6.
Another established practice is the custom fabrication of bench-rest actions. Exemplary are the actions produced by Ralph Stolle of Seabrook, Maryland, The Stolle Panda, having a rigidity of 3.9.times.10.sup.6, is an aluminum receiver weighing approximately 41.6 ounces. Another model, the Grissly, machined from steel and weighing approximately 104 ounces, yields a rigidity value of 11.0.times.10.sup.6. Commonly, the actions are of considerable exterior dimensions with a minimum sized ejection port and lacking a magazine opening or receiver port.
It is apparent from the foregoing discussion that the lack of rigidity in a conventional bolt action is a serious limiting factor to ultimate rifle action. A fact well-known to those skilled in the art. Unfortunately, prior art methods to increase rigidity have resulted in expensive receivers of substantially reduced versatility.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide improvements in rifle actions.
Another object of the invention is the provision of improvements especially adapted for use in connection with pre-existing commercially available bolt type actions.
And another object of the invention is to provide means and method for increasing the rigidity of a conventional bolt action.
Still another object of the immediate invention is the provision of means and method for substantially increasing rigidity while only minimally increasing weight.
Yet another object of the invention is to provide rigidizing means which preserve the function and appearance of the action.
Yet still another object of this invention is the provision of means for reinforcing the receivers which are substantially or totally obsecurable by the stock of the rifle.
And a further object of the invention is to provide rigidizing means which include optional means for varying the weight of a rifle.
Still a further object of the instant invention is the provision of stabilizing apparatus which includes a cartridge loading platform.
Yet a further object of the invention is to provide means and apparatus which may be readily practiced as a kit for retrofit to pre-existing action or incorporated into original manufacture.
And a further object of the invention is the provision of means and method, according to the above, which are relatively simple and inexpensive to effectuate.